This application claims Paris Convention priority of DE 101 03 275.7-12 filed Jan. 25, 2001 the complete disclosure of which is hereby incorporated by reference.
The invention relates to an arrangement comprising a sealing valve for pressure compensation within a container containing a fluid.
DE 41 35 711 C2 e.g. discloses a sealing valve arrangement comprising a sealing valve.
Sealing valves are required for the cells of storage batteries, wherein the sealing valve reliably prevents leakage of battery acid and gas under normal pressure conditions and opens at a defined pressure above atmospheric within the battery cell and discharges gas. Storage batteries of this type, in particular lead accumulators for automotive vehicles, are mass produced articles wherein the sealing valves must be produced at as little costs as possible.
The control channel of the conventional sealing valve provides a defined flow path for fluids which terminates at a sealing bead which permits defined application of pressure of this predetermined gas discharge location and produces improved, more controlled and finer response characteristics.
The tank lids of motor saws e.g. require valve operation for pressure above atmospheric and sub-atmospheric pressure to compensate the pressure within the container.
It is the underlying purpose of the invention to improve a conventional sealing valve such that the sealing valve assumes valve operation for pressure above atmospheric and sub-atmospheric pressure within the container.
This object is achieved in accordance with the invention by a sealing valve arrangement for a container containing a fluid. A supporting element comprising a control channel in its border region and a securing element comprising a passage channel are disposed on top of one another above the fluid containing chamber of the container. A sealing valve having smaller radial dimensions than these elements and a valve channel for connecting the control channel and the passage channel are also provided between the supporting element and the securing element. The sealing valve comprises a first sealing surface or edge for sealing the passage channel from the control channel, and a second sealing surface or edge for sealing the valve channel from the control channel. The sealing arrangement guarantees pressure compensation within the container in two directions, i.e. in case of pressure above atmospheric and sub-atmospheric pressure. An subatmospheric pressure of 100 mbar and an pressure above atmospheric of 300 mbar can be compensated by e.g. the sealing edges, appropriate selection of the material and the pretension. Pressure variations within predetermined limits can be reliably reduced. The sealing arrangement can be used as tank aerating and deaerating valve etc. It operates at different opening pressures depending on the direction. The container is sealed up to a certain pressure level. In case of sub-atmospheric pressure in the container, the sealing arrangement opens at a smaller pressure compared to pressure above atmospheric. The sealing action is achieved by axial pretension. The cross-section of the valve channel and the strength of the first sealing edge define the value of the opening pressure. In case of pressure above atmospheric in the container, the second sealing edge at the supporting element opens and reduces the pressure.
In a preferred embodiment of the invention, the sealing element is formed by a valve cone having inclined surfaces on which the second sealing edge abuts. The valve channel can be disposed onto the cone tip to achieve an arrangement which is easy to assemble and additionally has good response characteristics under pressure above atmospheric.
The valve function can be enhanced by providing one control channel on each side of the central axis of the supporting element.
Another subject matter of the invention is a sealing valve of a rubber-elastic material for container openings having a valve channel and, at its upper side, a first circumferential sealing edge formed on both sides of the valve channel, and at its lower side a second sealing edge formed around the valve channel. Recesses are provided in the material below the first sealing edge via which the response characteristics of the sealing valve can be controlled in case of sub-atmospheric pressure.